26 January, 1998

Hello Everyone!

We still are in the Cape Adare area, gathering information about the last 
ice age by looking at the clues the ice sheet left behind on the sea 
floor.  The Nathaniel B. Palmer is at:

70 degrees 56 minutes south latitude
169 degrees 53 minutes east longitude 

Yesterday I spent some time on the Bridge.  This is the place on the ship 
where they steer the boat.  It is up high and surrounded  by windows.  
Why do you think that is?

I spoke with Mr. Lee Crowe, Chief Officer of the Nathaniel B. Palmer.   
He has been working on the Palmer for 3 years.  When he is not on the 
ship, Mr. Crowe is at home with his family in Mississippi.  He has a 
daughter named Sarah who is 12 and a son named Josh who is 9. Mr. Crowe 
is here to steer the ship, assist the Captain and act as the Captain when 
needed, and oversee the ship operation and safety training of the crew.  
It is a job that takes many hours each day!

Mr. Crowe told me about the ice breaking capabilities of the Research 
Vessel Nathaniel B. Palmer.  She is an ice breaker with very powerful 
engines and a special hull (body). The hull is a double hull so that it 
is extra strong and can push through ice without being damaged.  The 
engines are not as powerful as some of the ships designed especially to 
escort other ships through the ice or break the ice channel into McMurdo 
Station each spring.  The Palmer's engines are designed to move through 
about three feet of ice.  The Palmer is made to allow us to work safely 
in ice. We actually try to avoid thick ice because it is not as efficient 
to go through - the ship uses more fuel when the breaking ice.

Before you can break through ice, you have to know something about it - 
you do not want the ship to get stuck!  Some Antarctic explorers have 
gotten their ships stuck in the ice.  My family named me for Ernest 
Shackleton.  Mr. Shackleton went to Antarctica to find a place where he 
could lead an expedition across the continent from Weddell Sea to Ross 
Sea.  His ship, Endurance, became trapped by sea ice in Weddell Sea for 
more than 11 months. The ship eventually was crushed, but the crew made 
it to safety after staying almost a year and a half in Antarctica. 
Knowing how ice forms and behaves is a good idea and will help us to 
avoid getting trapped or damaging the ship. We have an advantage over the 
early explorers, however - we get satellite weather reports and sea ice 
images so we can plan our path.

Sea ice forms each year around Antarctica.  It starts when the air 
temperatures fall and the surface ocean temperatures cool in the fall.  
Tiny ice crystals form; these are called frazzle ice.  The ice crystals 
start joining together, and a thin film of ice forms on the water 
surface.  The ice is called grease ice because the water looks like it 
has a layer of grease on it.  Eventually the ice plates grow larger and 
larger, forming plates that look like lily pads.  The plates have 
upturned edges because the plates bump into each other.  This is called 
pancake ice.  Pieces of pancake ice can get up to 20 feet across! Water 
freezing onto the bottom and snow falling onto the top help pancake ice 
to thicken. Pieces of pancake ice sometimes get pushed up onto each other 
(rafting), making the ice even thicker.  Eventually the pancakes join and 
a thin sheet of ice forms around Antarctica.  This blanket of ice doubles 
the size of Antarctica each year!  With warmer temperatures the sea ice 
melts back each spring.  Just think about all the animals in Antarctica.  
They get their food from the sea.   What do you think the animals do as 
the ice changes size through the year?

The pancake ice is also called pack ice.  The ice pack can be very close 
together and difficult to get through, or it can be pieces with lots of 
water between.  Sometimes the ice stays for more than a year - this is 
called multi-year ice.  It is harder than sea ice because the ice has 
very little salt in it - the salt has slowly separated out from the ice 
(remember your experiment making sea ice a few weeks ago?).  Ice that is 
attached to the coast line is called fast ice - it is "held fast."  Fast 
ice often is older than a year and is very hard and thicker than the 
annual sea ice.

The ship is designed to go through most annual sea ice in Antarctica - it 
is usually less than 3 feet thick.  When it moves through pack ice with a 
lot of water between the pieces, it pushes them out of the way.  When the 
ship gets to pack ice that does not have spaces between it or to thicker, 
harder fast ice, the ice has no where to go, except under the boat - it 
makes a lot of noise - like someone banging on water pipes with a hammer! 
 To break through the ice the ship "runs forward" so that its nose is on 
the ice - the weight of the boat breaks the ice.  Then the ship backs up 
and the powerful engines push it forward again, onto the next piece of 
ice.  Progress is slow!  Once when trying to deliver supplies to a 
Russian research station, Mr. Crowe spent 4 hours getting the ship a mile 
and a half closer to the station!

Mr. Crowe says that he misses his family when he is away, but he enjoys 
working in Antarctica because driving a ship in Antarctica is challenging 
- the environment makes him use all his boat-handling skills.  His 
favorite part of the job is working with the scientists collecting new 
information about how our Earth works. As he says "if you've got to work 
somewhere - Antarctica IS the place to be!"

More soon from the ice -

E. Shackleton Bear

P.S.  If you want to see some pictures from our cruise, look at Kim 
Giesting's journal  at this same website - I have sent some there!